The fortified drinks become very, very boring after a while as there are only very few flavours, all much the same as fruit yoghurt plus coffee and cocoa.
Blending frozen raspberries or strawberries and then mixing them into yoghurt or a similar sour milk product (if you can digest milk, that is) makes a change.
Blending soups is certainly a good idea, BUT, if you have made the soup with leeks or any other vegetable that tends to be a little stringy, sieve it as well, especially if you have had a stent inserted to widen the oesophagous. If you eat meat, a good old-fashioned chicken or beef broth strained through a fine sieve with a piece of muslin, scalded and stretched over the sieve ( hold it in place with clothes pegs, unless the cloth is a good deal wider than the sieve.) is nourishing.
If you have to do your own cooking, and don't feel up to it, Knorr's powdered soups in packets, are extremely useful in your situation. And of course, Bovril comes into its own here, too.
Can you manage to swallow mashed potatoes if they are very smooth and have had a lot of milk or vegetable stock added, so they more nearly resemble gruel?
A raw egg, well beaten and mixed with buttermilk and sugar is another possiblity.
You can blend cooked mince, but it looks quite disgusting, so that may put you off. I invented the dish when a cat had been bitten on the jaw-bone by a rat. The bite swelled, and even after the boil burst and the vet prescribed antibiotics, the poor cat found chewing painful, but was hungry enough, and after all a cat, so unperturbed by the look of minced cat-food!
I hope your consultant is offering alternative treatment to the operation that has been refused.
Malt beer with either a very low alcohol percentage, or none will provide some calories, as will the soft drinks we are usually told to avoid, and at the very least give you a different taste to the endless, boring menu of blended soup, milk puddings and yoghurt.